Cleaning robot and recharge path determining method therefor

Abstract

There is provided a cleaning robot system including a charging station and a cleaning robot. The charging station includes multiple positioning beacons. The cleaning robot includes an image sensor and a processor. The image sensor is used to acquire light generated by the multiple positioning beacons on the charging station and generate an image frame. The processor is electrically connected to the image sensor, and used to calculate a relative position with respect to the charging station according to beacon images of the multiple positioning beacons in the image frame to determine a recharge path accordingly.

What is claimed is: 
     
       1. A cleaning robot system, comprising:
 a charging station comprising multiple positioning beacons, the multiple positioning beacons including a first positioning beacon arranged at a first surface of the charging station and a second positioning beacon arranged at a second surface, opposite to the first surface, of the charging station; and 
 a cleaning robot, comprising:
 an image sensor configured to capture light generated by the multiple positioning beacons on the charging station and generate an image frame; 
 a motor; and 
 a processor electrically connected to the image sensor and the motor, and configured to
 calculate a relative position of the cleaning robot with respect to the charging station according to beacon images of the multiple positioning beacons in the image frame, and 
 drive the motor according to the relative position to control the cleaning robot to return to the charging station for recharging, 
 
 
 wherein when a relative angle between the cleaning robot with respect to a front surface, which connects the first and second surfaces, of the charging station exceeds a predetermined angle, the image sensor of the cleaning robot does not capture the light generated by one of the first positioning beacon and the second positioning beacon, and 
 upon the image sensor not capturing the light generated by one of the first positioning beacon and the second positioning beacon, the processor sends a control signal to rotate the charging station till the light generated by all the multiple positioning beacons arranged at different surfaces are captured by the image sensor and then the processor calculates the relative position, and 
 the first positioning beacon is protruded out from the first surface and the second positioning beacon is protruded out from the second surface to cause the light from both the first positioning beacon and the second positioning beacon to be acquired by the cleaning robot to form beacon images when the cleaning robot is in front of the front surface of the charging station. 
 
     
     
       2. The cleaning robot system as claimed in  claim 1 , wherein the multiple positioning beacons are multiple active light sources or multiple passive light sources. 
     
     
       3. The cleaning robot system as claimed in  claim 2 , wherein
 the cleaning robot further comprises an illumination light source, and 
 the charging station further comprises a charging electrode configured to reflect light generated by the illumination light source as one of the multiple passive light sources. 
 
     
     
       4. The cleaning robot system as claimed in  claim 1 , wherein the multiple positioning beacons have identical or different characteristics. 
     
     
       5. The cleaning robot system as claimed in  claim 1 , wherein the multiple positioning beacons are arranged at at least two different heights. 
     
     
       6. The cleaning robot system as claimed in  claim 1 , wherein the charging station is rotatable. 
     
     
       7. The cleaning robot system as claimed in  claim 1 , wherein
 the multiple positioning beacons further include a third position beacon located at the front surface, and 
 when the cleaning robot is in front of the front surface of the charging station, beacon images of the first positioning beacon, the second positioning beacon and the third position beacon form a triangle shape in the image frame. 
 
     
     
       8. The cleaning robot system as claimed in  claim 7 , wherein the processor is further configured to
 determine the relative angle according to distances between the beacon images of the first positioning beacon, the second positioning beacon and the third position beacon from a predetermined look up table. 
 
     
     
       9. A cleaning robot, comprising:
 an image sensor configured to
 capture light generated by multiple positioning beacons having a predetermined characteristic, the multiple positioning beacons including a first positioning beacon arranged at a first surface of a charging station and a second positioning beacon arranged at a second surface, opposite to the first surface, of the charging station, and 
 generate an image frame; 
 
 a motor; and 
 a processor electrically connected to the image sensor and the motor, and configured to
 calculate a relative position of the cleaning robot with respect to the multiple positioning beacons according to beacon images of the multiple positioning beacons in the image frame, and 
 drive the motor according to the relative position to control the cleaning robot to move to a predetermined position with respect to the multiple positioning beacons, 
 
 wherein when a relative angle between the cleaning robot with respect to a surface connecting the first and second surfaces exceeds a predetermined angle, the image sensor of the cleaning robot does not capture the light generated by one of the first positioning beacon and the second positioning beacon, and 
 upon the image sensor not capturing the light generated by one of the first positioning beacon and the second positioning beacon, the processor sends a control signal to change an emission direction of the multiple positioning beacons till the light generated by all the multiple positioning beacons arranged at different surfaces are captured by the image sensor and then the processor calculates the relative position, and 
 the first positioning beacon is protruded out from the first surface and the second positioning beacon is protruded out from the second surface to cause the light from both the first positioning beacon and the second positioning beacon to be acquired by the cleaning robot to form beacon images when the cleaning robot is in front of the charging station. 
 
     
     
       10. The cleaning robot as claimed in  claim 9 , wherein the motor comprises:
 a first motor configured to control the cleaning robot to move forward; and 
 a second motor configured to control the cleaning robot to rotate. 
 
     
     
       11. The cleaning robot as claimed in  claim 10 , wherein the processor is further configured to control the second motor to cause the cleaning robot to perform an in situ rotation when the image frame does not contain any beacon image. 
     
     
       12. The cleaning robot as claimed in  claim 9 , further comprising an illumination light source configured to emit light toward the multiple positioning beacons. 
     
     
       13. The cleaning robot as claimed in  claim 9 , further comprising a transmitter configured to transmit the control signal. 
     
     
       14. The cleaning robot as claimed in  claim 9 , wherein the predetermined position comprises a predetermined distance and a predetermined angle, and the processor is configured to
 control the cleaning robot to move to the predetermined distance from the multiple positioning beacons at first, and then control the cleaning robot to continuously move, at the predetermined distance, to the predetermined angle with respect to the multiple positioning beacons, or 
 control the cleaning robot to move to the predetermined angle with respect to the multiple positioning beacons at first, and then control the cleaning robot to continuously move, at the predetermined angle, to the predetermined distance from the multiple positioning beacons. 
 
     
     
       15. A recharge path determining method for a cleaning robot system, the cleaning robot system comprising a charging station that has multiple positioning beacons and a cleaning robot that has an image sensor and a processor, the multiple positioning beacons including a first positioning beacon arranged at a first surface of the charging station and a second positioning beacon arranged at a second surface, opposite to the first surface, of the charging station, the determining method comprising:
 capturing, by the image sensor, light generated by the multiple positioning beacons on the charging station and generating, by the image sensor, an image frame; 
 calculating, by the processor, a relative position of the cleaning robot with respect to the charging station according to beacon images of the multiple positioning beacons in the image frame; 
 controlling, by the processor, the cleaning robot according to the relative position to return to the charging station for recharging; 
 identifying, by the processor, whether a number of the beacon images is smaller than a predetermined number; and 
 upon the number of the beacon images being smaller than the predetermined number, rotating the charging station till the number of the beacon images associated with the multiple positioning beacons arranged at different surfaces is equal to the predetermined number and then calculating the relative position by the processor, 
 wherein the first positioning beacon is protruded out from the first surface and the second positioning beacon is protruded out from the second surface to cause the light from both the first positioning beacon and the second positioning beacon to be acquired by the cleaning robot to form beacon images when the cleaning robot is in front of the charging station. 
 
     
     
       16. The determining method as claimed in  claim 15 , wherein the cleaning robot further comprises an illumination light source, and the determining method further comprises:
 controlling the illumination light source to emit light corresponding to the light capturing of the image sensor. 
 
     
     
       17. The determining method as claimed in  claim 15 , further comprising:
 distinguishing, by the processor, different positioning beacons according to different characteristics of the multiple positioning beacons. 
 
     
     
       18. The determining method as claimed in  claim 15 , further comprising:
 transmitting, by the cleaning robot, a control signal to the charging station to rotate the charging station. 
 
     
     
       19. The determining method as claimed in  claim 15 , further comprising:
 controlling, by the processor, a field of view of the image sensor when the image frame does not contain any beacon image.